This invention relates to a novel valve for pressurized liquid fire extinguishers. More specifically, my invention improves the distance pressurized extinguishant may be thrown from a portable fire extinguisher.
Some forms of fire, such as chemical fires, burn at very high temperatures. Approaching these fires is very difficult due to the extreme heat or dangerous fumes. Conventional portable Halon 1301 type extinguishers are only capable of throwing extinguishant about four to eight feet. My invention doubles this throw distance by using a nonobstructing manual extinguisher valve and smooth discharge conduit.
Many manually operable extinguisher valves exist. One example of this type of valve is shown in U.S. Pat. No. 3,009,681, issued to P. M. Carter, et.al., Dec. 30, 1955. It discloses a pair of frustoconical valve heads seated in a tapered discharge passage. A rod attached to the heads opens and closes the extinguisher. When the extinguisher is open, the rod remains in the discharge passage inducing turbulence in the discharging extinguishant and partially blocking its flow. The turbulence created by the rod reduces the pressure at the exit nozzle. The reduced pressure at the exit nozzle reduces the exit velocity and maximum distance the extinguishant can travel.
Another type of common extinguisher valve uses a foil diaphram to seal the extinguishant in the bottle until needed. To discharge the extinguisher, the operator causes a knife to tear the diaphram and release the pressurized extinguishant. An example of this type of extinguisher valve is shown in my U.S. Pat. No. 4,476,937. The ruptured diaphram does not significantly block the flow of extinguishant, however, the extinguisher cannot be partially discharged. Once the diaphram is shorn, the entire charge of extinguishant is released. Also, such a valve requires rebuilding before it can be reused.
The principle aim of my invention is to reduce the turbulence induced pressure drop in the discharging extinguishant by keeping the discharge path as obstruction free as possible. The increased throw distance of my invention makes the extinguisher more effective at putting out fires and safer for operators because they need not approach the fire as closely.
Turbulence in the extinguisher is caused or enhanced by obstructions, sharp angles or rough surfaces in the discharge passage. By making the discharge passage as obstruction free as possible, the amount of turbulence in the extinguishant and the resultant pressure drop at the exit nozzle is kept to a minimum. This increases both the exit velocity and the maximum throw distance of the extinguishant. Increasing the exit velocity allows more extinguishant to be directed to the fire in a shorter period of time.
Objects of the invention are to provide a fire extinguisher valve wherein:
1. The valve has no blockage of the extinguisher discharge path to reduce turbulence and pressure drops in the extinguishant, whereby the extinguishant has a fast exit velocity and longer throw distance.
2. The valve provides a leak-proof seal for long time non-use storage.
3. The valve is fast opening.
4. The valve may be reused without any rebuilding.
5. The valve has smooth interior surfaces to further reduce turbulence and increase the extinguishant throw.
The extinguisher uses a poppet type valve to release extinguishant. Two tappet rods recessed within the valve housing on either side of the discharge passage open and closed the poppet valve. The tappets are placed outside of the discharge path and do not interfere with the extinguishant flow or create turbulence when the extinguisher is used. The discharge passage has smooth interior surfaces and a smoothly curved path from the bottle to the nozzle. The shape and finish of the unobstructed discharge path reduce the turbulence of the discharging extinguishant which increases both the maximum throw distance and exit velocity.
My invention may be used with any type of pressurized fire extinguishant but is particularly well suited for portable pressurized Halon type extinguishers.